The Volokh Conspiracy
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Trump's Plan to Use the Alien Enemies Act of 1798 as a Tool for Mass Deportation
The plan is illegal. But courts might refuse to strike it down based on the "political questions" doctrine.
Donald Trump recently announced his intention to use the Alien Enemies Act of 1798 as a tool for mass deportation of immigrants. The Alien Enemies Act is a component of the notorious Alien And Sedition Acts. It's the only part of that legislation that remains on the books today. Unlike the more sweeping Alien Friends Act, which gave the president broad power to deport and bar any "aliens as he shall judge dangerous to the peace and safety of the United States," and was therefore rightly denounced as unconstitutional by James Madison, Thomas Jefferson, and others, the Alien Enemies Act allows detention and removal only when there "is a declared war between the United States and any foreign nation or government, or any invasion or predatory incursion is perpetrated, attempted, or threatened against the territory of the United States by any foreign nation or government." In that event, the president is given the power to detain or remove "all natives, citizens, denizens, or subjects of the hostile nation or government, being of the age of fourteen years and upward, who shall be within the United States and not actually naturalized."
Katherine Yon Ebright of the Brennan Center has an excellent explanation of why the Alien Enemies Act cannot legally be used against migrants from countries with which the US is not at war. Here's her summary of her analysis:
As the Supreme Court and past presidents have acknowledged, the Alien Enemies Act is a wartime authority enacted and implemented under the war power. When the Fifth Congress passed the law and the Wilson administration defended it in court during World War I, they did so on the understanding that noncitizens with connections to a foreign belligerent could be "treated as prisoners of war" under the "rules of war under the law of nations." In the Constitution and other late-1700s statutes, the term invasion is used literally, typically to refer to large-scale attacks. The term predatory incursion is also used literally in writings of that period to refer to slightly smaller attacks like the 1781 Raid on Richmond led by American defector Benedict Arnold.
Today, some anti-immigration politicians and groups urge a non-literal reading of invasion and predatory incursion so that the Alien Enemies Act can be invoked in response to unlawful migration and cross-border narcotics trafficking. These politicians and groups view the Alien Enemies Act as a turbocharged deportation authority. But their proposed reading of the law is at odds with centuries of legislative, presidential, and judicial practice, all of which confirm that the Alien Enemies Act is a wartime authority. Invoking it in peacetime to bypass conventional immigration law would be a staggering abuse.
She makes several other good points, as well. If you're interested in this issue, read the whole thing!
I would add that the "invasion" or "predatory incursion" in question must be perpetrated by a "foreign nation or government." That excludes illegal migration or drug smuggling perpetrated by private individuals, which is what we see at the southern border today. One can argue that use of the word "nation" in addition to "government" means the former has a different meaning from the latter. Perhaps so. But "nation" still doesn't include private individuals. Rather, it could apply to state-like entities that are not recognized governments. For instance, the Hamas terrorist organization that brutally attacked Israel on Oct. 7, 2023 is not a recognized government, but did - at least until recently - have state-like control over Gaza. The same could be said for some Founding-era Indian nations (which the US and European states didn't recognize as full-fledged governments) and groups like the Barbary pirates, who were agents of Arab north African states.
Elsewhere, I have explained why Founding-era understandings of "invasion" are limited to large-scale armed attacks, and do not cover things like illegal migration or drug smuggling (for more detail, see my amicus brief in United States v. Abbott).
Despite the strong legal arguments against it, there is a chance Trump could succeed in using the Alien Enemies Act as a tool for detention and deportation. As Ebright notes, courts might rule that the definitions of "invasion" and "predatory incursion" are "political questions" that courts aren't allowed to address. Several previous court decisions have held that the definition of "invasion" in the Constitution is a political question (thereby preventing state governments from invoking broad definitions of invasion under the Invasion Clause of Article IV in order to be able to "engage in war" in war without federal authorization), though many have simultaneously held that an illegal migration does not qualify as "invasion" because an invasion requires a large-scale armed attack (see pp. 20-22 of my amicus brief).
Ebright argues (correctly, I think) that even if the definition of "invasion" is usually a political question, the use of the Alien Enemies Act as a tool for mass detention and deportation of migrants from countries with which the US is not at war should fall within the exception for "an obvious mistake" or "manifestly unauthorized exercise of power" (Baker v. Carr (1962)). I would add that the entire political question doctrine is an incoherent mess, and courts should not extend it further.
Nonetheless, there is a danger they could apply it here, and thereby let Trump get away with a grave abuse of power that could potentially harm many thousands of people. Mass deportations of the kind envisioned by Trump would create disruption, increase prices and cause shortages. They also destroys more American jobs than they creates, because many U.S. citizens work in industries that depend on goods produced by undocumented workers. In addition, large-scale detention and deportation routinely sweeps in large numbers of US citizens, detained by mistake because of poor-to-nonexistent due process protections.
It's also worth noting that the Alien Enemies Act applies to any migrants from the relevant countries who have not been "naturalized," which includes legal migrants even permanent resident green card holders. If Trump is able to use it at all, it could be deployed against legal immigrants no less than illegal ones. And he and his allies have repeatedly made clear they want to slash legal migration no less than the illegal kind.
If Trump returns to power, it is possible this particular plan will be stopped by the courts. But that is far from certain. Ebright also recommends Congress simply repeal the Alien Enemies Act (there are plenty of other tools to deal with actual threats to national security); I agree, but it's unlikely to happen anytime soon. Thus, the only surefire way to block this dangerous abuse of power is to defeat Trump in the election.
UPDATE: Prof. Michael Ramsey commented on this post here. I responded in a follow-up post.
